hi i've found this thread searching for amd microcode : is this microcode somehow necessary, i notice after installing it the message disapeared,
but the problems i experimented before remains the same :

i still have to reboot (blind in a console via ctrl-alt-fx, login as root, or via pwr button) for
after closing the lid of laptop, waking up works but screen remains dark wich i thought was because of
lack of amd support...

The ability to load microcode updates has just been added for AMD CPUs as well (it's been around for intel CPUs for quite a while). These microcode updates are supposed to fix (circumvent) known hardware bugs of the CPU, to fix broken behaviour caused by faulty CPU engineering or production (think of FDIV or F00F, which were the reasons why Intel developed this mechanism for their following CPU lines) for certain model ranges.

While the CPU vendors suggest installing them, doing so is not required. The CPU ships without them, workarounds are added as they're found/ fixed (e.g. not immediately - and not necessarily for your CPU at all) and they aren't shipped with windows either (at least not anything found after the media has gone gold), while they may be added to later service packs or updates). Especially for AMD CPUs, given that this functionality has just been added to the kernel in 3.4, the boot messages complaining about missing ucode updates are a bit over the top and sensationalist. In addition these ucode updates are inherently non-free and most of the time badly versioned or documented at all, if you find them in the first place…

So yes, installing them is suggested - but my guess is that none are installed on the vast majority of computer systems (regardless of the OS, incl. windows), which are still working, so they can't be that critical. Also keep in mind that they're just papering over hardware bugs (with better or worse success, respectively performance penalty (if certain functionality has to be disabled)), which allows the CPU vendors to decline replacing their faulty product (yes, due to their complexity, every modern CPU has a mile long list of known and/ or secret errata).

Personally, I usually don't install them -mostly out of laziness- haven't died yet.